PNG background transparency

Question

I was wondering if anyone made a splashscreen using a partly transparent png file (can't use gif, it looks like garbage). I tried this:

#include <ButtonConstants.au3>
#include <MsgBoxConstants.au3>
#include <StructureConstants.au3>
#include <WinAPIConstants.au3>
#include <GDIPlus.au3>
#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>


_GDIPlus_Startup()
Global Const $SC_DRAGMOVE = 0xF012
Global $iW, $iH, $hImage, $hBitmap, $hGUI
$hImage = _GDIPlus_BitmapCreateFromFile("C:\Program Files\AutoIt3\Examples\GUI\Torus.png")
$hBitmap = _GDIPlus_BitmapCreateHBITMAPFromBitmap($hImage)
$iW = _GDIPlus_ImageGetWidth($hImage)
$iH = _GDIPlus_ImageGetHeight($hImage)
$hGUI = GUICreate("", $iW, $iH, -1, -1, $WS_POPUP, $WS_EX_LAYERED)
GUISetState()
_WinAPI_BitmapDisplayTransparentInGUI($hBitmap, $hGUI)
GUIRegisterMsg($WM_LBUTTONDOWN, "_WM_LBUTTONDOWN")


Do
Until GUIGetMsg() = $GUI_EVENT_CLOSE

_WinAPI_DeleteObject($hBitmap)
_GDIPlus_BitmapDispose($hImage)
_GDIPlus_Shutdown()
GUIDelete()

Func _WinAPI_BitmapDisplayTransparentInGUI(ByRef $hHBitmap, ByRef $hGUI, $iOpacity = 0xFF, $bReleaseGDI = True)
    If Not BitAND(GUIGetStyle($hGUI)[1], $WS_EX_LAYERED) = $WS_EX_LAYERED Then Return SetError(1, 0, 0)
    Local $tDim = DllStructCreate($tagBITMAP)
    If Not _WinAPI_GetObject($hHBitmap, DllStructGetSize($tDim), DllStructGetPtr($tDim)) Then Return SetError(2, 0, 0)
    Local $tSize = DllStructCreate($tagSIZE), $tSource = DllStructCreate($tagPOINT), $tBlend = DllStructCreate($tagBLENDFUNCTION)
    Local Const $hScrDC = _WinAPI_GetDC(0), $hMemDC = _WinAPI_CreateCompatibleDC($hScrDC), $hOld = _WinAPI_SelectObject($hMemDC, $hHBitmap)
    $tSize.X = $tDim.bmWidth
    $tSize.Y = $tDim.bmHeight
    $tBlend.Alpha = $iOpacity
    $tBlend.Format = 1
    _WinAPI_UpdateLayeredWindow($hGUI, $hScrDC, 0, DllStructGetPtr($tSize), $hMemDC, DllStructGetPtr($tSource), 0, DllStructGetPtr($tBlend), $ULW_ALPHA)
    _WinAPI_ReleaseDC(0, $hScrDC)
    _WinAPI_SelectObject($hMemDC, $hOld)
    _WinAPI_DeleteDC($hMemDC)
    If $bReleaseGDI Then _WinAPI_DeleteObject($hHBitmap)
    Return True
EndFunc

Func _WM_LBUTTONDOWN($hWnd, $iMsg, $wParam, $lParam)
    _SendMessage($hGUI, $WM_SYSCOMMAND, $SC_DRAGMOVE, 0)
EndFunc   ;==>_WM_LBUTTONDOWN

But the background gets colored (no transparency). Any pointers would be great.

Answer 1

I use a snippet from AutoIt's forums (I would go there for support first if you haven't). It works well. Couple of glitches but nothing you can't wiggle out of in a case to case basis. Try it!

#include <GDIPlus.au3>
#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>

 _GDIPlus_Startup()

$hSplashlogo = _GDIPlus_ImageLoadFromFile("C:\Program Files (x86)\AutoIt3\Examples\GUI\Torus.png")


$logoheight = (@DesktopHeight/2) - (_GDIPlus_ImageGetHeight($hSplashlogo)/2) - 50
$logowidth = (@DesktopWidth /2) - (_GDIPlus_ImageGetWidth($hSplashlogo)/2)
$SplashGUIlogo = GUICreate("", _GDIPlus_ImageGetWidth($hSplashlogo), _GDIPlus_ImageGetHeight($hSplashlogo), $logowidth, $logoheight, $WS_POPUP, BitOR($WS_EX_LAYERED,$WS_EX_TOOLWINDOW))
_SetBitmap($SplashGUIlogo, $hSplashlogo, 255, _GDIPlus_ImageGetWidth($hSplashlogo), _GDIPlus_ImageGetHeight($hSplashlogo))
GUISetState(@SW_SHOWNA, $SplashGUIlogo)


While 1
    Sleep(20)
WEnd

 _GDIPlus_Shutdown()


Func _SetBitmap($hGUI, $hImage, $iOpacity, $n_width = 200, $n_height = 200)
    Local $hScrDC, $hMemDC, $hBitmap, $hOld, $pSize, $tSize, $pSource, $tSource, $pBlend, $tBlend

    $hScrDC = _WinAPI_GetDC(0)
    $hMemDC = _WinAPI_CreateCompatibleDC($hScrDC)
    $hBitmap = _GDIPlus_BitmapCreateHBITMAPFromBitmap($hImage)
    $hOld = _WinAPI_SelectObject($hMemDC, $hBitmap)
    $tSize = DllStructCreate($tagSIZE)
    $pSize = DllStructGetPtr($tSize)
    DllStructSetData($tSize, "X", $n_width)
    DllStructSetData($tSize, "Y", $n_height)
    $tSource = DllStructCreate($tagPOINT)
    $pSource = DllStructGetPtr($tSource)
    $tBlend = DllStructCreate($tagBLENDFUNCTION)
    $pBlend = DllStructGetPtr($tBlend)
    DllStructSetData($tBlend, "Alpha", $iOpacity)
    DllStructSetData($tBlend, "Format", 1)
    _WinAPI_UpdateLayeredWindow($hGUI, $hScrDC, 0, $pSize, $hMemDC, $pSource, 0, $pBlend, $ULW_ALPHA)
    _WinAPI_ReleaseDC(0, $hScrDC)
    _WinAPI_SelectObject($hMemDC, $hOld)
    _WinAPI_DeleteObject($hBitmap)
    _WinAPI_DeleteDC($hMemDC)
EndFunc   ;==>_SetBitmap

I made a variation that loads the bitmap from a URL instead of a path; if you need it let me know!